China's stock index futures opened mixed Friday, with the contract for settlement in June, which is most actively traded, fell 8 points to open at 2,740.

The contract expiring in July dropped 0.2 point to open at 2,766.8.

The September contract opened at 2,790.8, down 13 points from the previous trading day.

The December contract added 10.2 points to open at 2,852.4.

The stock-index contracts, agreements to buy or sell the Hushen 300 Index at a present value on an agreed date, are designed to allow investors to bet on and profit from both gains and declines in the market.

The index futures was launched at the China Financial Futures Exchange (CFFEX) and started trading from April 16, 2010. The CFFEX has set the base value for all the four contracts at 3,399 points.